File	Doc	Category	Size	Date	Package
Krb5LoginModule.java	API Doc	Java SE 5 API	36667	Fri Aug 26 14:56:16 BST 2005	com.sun.security.auth.module

Krb5LoginModule

• java.lang.Object

useFirstPass if, true, this LoginModule retrieves the
username and password from the module's shared state,
using "javax.security.auth.login.name" and
"javax.security.auth.login.password" as the respective
keys. The retrieved values are used for authentication.
If authentication fails, no attempt for a retry
is made, and the failure is reported back to the
calling application.

tryFirstPass if, true, this LoginModule retrieves the
the username and password from the module's shared
state using "javax.security.auth.login.name" and
"javax.security.auth.login.password" as the respective
keys. The retrieved values are used for
authentication.
If authentication fails, the module uses the
CallbackHandler to retrieve a new username
and password, and another attempt to authenticate
is made. If the authentication fails,
the failure is reported back to the calling application

storePass if, true, this LoginModule stores the username and
password obtained from the CallbackHandler in the
modules shared state, using
"javax.security.auth.login.name" and
"javax.security.auth.login.password" as the respective
keys. This is not performed if existing values already
exist for the username and password in the shared
state, or if authentication fails.

clearPass if, true, this LoginModule clears the
username and password stored in the module's shared
state after both phases of authentication
(login and commit) have completed.

Fields Summary
private Subject	subject
private CallbackHandler	callbackHandler
private Map	sharedState
private Map	options
private boolean	debug
private boolean	storeKey
private boolean	doNotPrompt
private boolean	useTicketCache
private boolean	useKeyTab
private String	ticketCacheName
private String	keyTabName
private String	princName
private boolean	useFirstPass
private boolean	tryFirstPass
private boolean	storePass
private boolean	clearPass
private boolean	refreshKrb5Config
private boolean	renewTGT
private boolean	succeeded
private boolean	commitSucceeded
private String	username
private EncryptionKey[]	encKeys
private Credentials	cred
private PrincipalName	principal
private KerberosPrincipal	kerbClientPrinc
private KerberosTicket	kerbTicket
private KerberosKey[]	kerbKeys
private StringBuffer	krb5PrincName
private char[]	password
private static final String	NAME
private static final String	PWD
static final ResourceBundle	rb

Constructors Summary

Methods Summary
public boolean	abort() This method is called if the LoginContext's overall authentication failed. (the relevant REQUIRED, REQUISITE, SUFFICIENT and OPTIONAL LoginModules did not succeed). If this LoginModule's own authentication attempt succeeded (checked by retrieving the private state saved by the login and commit methods), then this method cleans up any state that was originally saved. exception LoginException if the abort fails. return false if this LoginModule's own login and/or commit attempts failed, and true otherwise. if (succeeded == false) { return false; } else if (succeeded == true && commitSucceeded == false) { // login succeeded but overall authentication failed succeeded = false; cleanKerberosCred(); } else { // overall authentication succeeded and commit succeeded, // but someone else's commit failed logout(); } return true;
private void	attemptAuthentication(boolean getPasswdFromSharedState) process the configuration options Get the TGT either out of cache or from the KDC using the password entered Check the permission before getting the TGT /* * Check the creds cache to see whether * we have TGT for this client principal */ if (krb5PrincName != null) { try { principal = new PrincipalName (krb5PrincName.toString(), PrincipalName.KRB_NT_PRINCIPAL); } catch (KrbException e) { LoginException le = new LoginException(e.getMessage()); le.initCause(e); throw le; } } try { if (useTicketCache) { // ticketCacheName == null implies the default cache if (debug) System.out.println("Acquire TGT from Cache"); cred = Credentials.acquireTGTFromCache (principal, ticketCacheName); if (cred != null) { // check to renew credentials if (!isCurrent(cred)) { if (renewTGT) { cred = renewCredentials(cred); } else { // credentials have expired cred = null; if (debug) System.out.println("Credentials are" + " no longer valid"); } } } if (cred != null) { // get the principal name from the ticket cache if (principal == null) { principal = cred.getClient(); } } if (debug) { System.out.println("Principal is " + principal); if (cred == null) { System.out.println ("null credentials from Ticket Cache"); } } } // cred = null indicates that we didn't get the creds // from the cache or useTicketCache was false if (cred == null) { // We need the principal name whether we use keytab // or AS Exchange if (principal == null) { promptForName(getPasswdFromSharedState); principal = new PrincipalName (krb5PrincName.toString(), PrincipalName.KRB_NT_PRINCIPAL); } if (useKeyTab) { encKeys = EncryptionKey.acquireSecretKeys(principal, keyTabName); if (debug) { if (encKeys != null) System.out.println ("principal's key obtained from the keytab"); else System.out.println ("Key for the principal " + principal + " not available in " + ((keyTabName == null) ? "default key tab" : keyTabName)); } } // We can't get the key from the keytab so prompt if (encKeys == null) { promptForPass(getPasswdFromSharedState); encKeys = EncryptionKey.acquireSecretKeys( password, principal.getSalt()); } // Get the TGT using AS Exchange if (debug) { System.out.println("principal is " + principal); System.out.println("Acquire TGT using AS Exchange"); HexDumpEncoder hd = new HexDumpEncoder(); for (int i = 0; i < encKeys.length; i++) { System.out.println("EncryptionKey: keyType=" + encKeys[i].getEType() + " keyBytes (hex dump)=" + hd.encode(encKeys[i].getBytes())); } } cred = Credentials.acquireTGT(principal, encKeys); // we should hava a non-null cred if (cred == null) { throw new LoginException ("TGT Can not be obtained from the KDC "); } } } catch (KrbException e) { LoginException le = new LoginException(e.getMessage()); le.initCause(e); throw le; } catch (IOException ioe) { LoginException ie = new LoginException(ioe.getMessage()); ie.initCause(ioe); throw ie; }
private void	cleanKerberosCred() Clean Kerberos credentials // Clean the ticket and server key try { if (kerbTicket != null) kerbTicket.destroy(); if (kerbKeys != null) { for (int i = 0; i < kerbKeys.length; i++) { kerbKeys[i].destroy(); } } } catch (DestroyFailedException e) { throw new LoginException ("Destroy Failed on Kerberos Private Credentials"); } kerbTicket = null; kerbKeys = null; kerbClientPrinc = null;
private void	cleanState() Clean out the state // save input as shared state only if // authentication succeeded if (succeeded) { if (storePass && !sharedState.containsKey(NAME) && !sharedState.containsKey(PWD)) { sharedState.put(NAME, username); sharedState.put(PWD, password); } } username = null; password = null; if (krb5PrincName != null && krb5PrincName.length() != 0) krb5PrincName.delete(0, krb5PrincName.length()); krb5PrincName = null; if (clearPass) { sharedState.remove(NAME); sharedState.remove(PWD); }
public boolean	commit() This method is called if the LoginContext's overall authentication succeeded (the relevant REQUIRED, REQUISITE, SUFFICIENT and OPTIONAL LoginModules succeeded). If this LoginModule's own authentication attempt succeeded (checked by retrieving the private state saved by the login method), then this method associates a Krb5Principal with the Subject located in the LoginModule. It adds Kerberos Credentials to the the Subject's private credentials set. If this LoginModule's own authentication attempted failed, then this method removes any state that was originally saved. exception LoginException if the commit fails. return true if this LoginModule's own login and commit attempts succeeded, or false otherwise. /* * Let us add the Krb5 Creds to the Subject's * private credentials. The credentials are of type * KerberosKey or KerberosTicket */ if (succeeded == false) { return false; } else { if (cred == null) { succeeded = false; throw new LoginException("Null Client Credential"); } if (subject.isReadOnly()) { cleanKerberosCred(); throw new LoginException("Subject is Readonly"); } /* * Add the Principal (authenticated identity) * to the Subject's principal set and * add the credentials (TGT or Service key) to the * Subject's private credentials */ Set privCredSet = subject.getPrivateCredentials(); Set princSet = subject.getPrincipals(); kerbClientPrinc = new KerberosPrincipal(principal.getName()); // create Kerberos Ticket kerbTicket = Krb5Util.credsToTicket(cred); if (storeKey) { if (encKeys == null || encKeys.length <= 0) { succeeded = false; throw new LoginException("Null Server Key "); } kerbKeys = new KerberosKey[encKeys.length]; for (int i = 0; i < encKeys.length; i ++) { Integer temp = encKeys[i].getKeyVersionNumber(); kerbKeys[i] = new KerberosKey(kerbClientPrinc, encKeys[i].getBytes(), encKeys[i].getEType(), (temp == null? 0: temp.intValue())); } } // Let us add the kerbClientPrinc,kerbTicket and kerbKey (if // storeKey is true) if (!princSet.contains(kerbClientPrinc)) princSet.add(kerbClientPrinc); if (!privCredSet.contains(kerbTicket)) privCredSet.add(kerbTicket); if (storeKey) { for (int i = 0; i < kerbKeys.length; i++) { if (!privCredSet.contains(kerbKeys[i])) { privCredSet.add(kerbKeys[i]); } encKeys[i].destroy(); encKeys[i] = null; if (debug) { System.out.println("Added server's key" + kerbKeys[i]); System.out.println("\t\t[Krb5LoginModule] " + "added Krb5Principal " + kerbClientPrinc.toString() + " to Subject"); } } } } commitSucceeded = true; if (debug) System.out.println("Commit Succeeded \n"); return true;
public void	initialize(javax.security.auth.Subject subject, javax.security.auth.callback.CallbackHandler callbackHandler, java.util.Map sharedState, java.util.Map options) Initialize this LoginModule. param subject the Subject to be authenticated. param callbackHandler a CallbackHandler for communication with the end user (prompting for usernames and passwords, for example). param sharedState shared LoginModule state. param options options specified in the login Configuration for this particular LoginModule. this.subject = subject; this.callbackHandler = callbackHandler; this.sharedState = sharedState; this.options = options; // initialize any configured options debug = "true".equalsIgnoreCase((String)options.get("debug")); storeKey = "true".equalsIgnoreCase((String)options.get("storeKey")); doNotPrompt = "true".equalsIgnoreCase((String)options.get ("doNotPrompt")); useTicketCache = "true".equalsIgnoreCase((String)options.get ("useTicketCache")); useKeyTab = "true".equalsIgnoreCase((String)options.get("useKeyTab")); ticketCacheName = (String)options.get("ticketCache"); keyTabName = (String)options.get("keyTab"); princName = (String)options.get("principal"); refreshKrb5Config = "true".equalsIgnoreCase((String)options.get("refreshKrb5Config")); renewTGT = "true".equalsIgnoreCase((String)options.get("renewTGT")); tryFirstPass = "true".equalsIgnoreCase ((String)options.get("tryFirstPass")); useFirstPass = "true".equalsIgnoreCase ((String)options.get("useFirstPass")); storePass = "true".equalsIgnoreCase((String)options.get("storePass")); clearPass = "true".equalsIgnoreCase((String)options.get("clearPass")); if (debug) { System.out.print("Debug is " + debug + " storeKey " + storeKey + " useTicketCache " + useTicketCache + " useKeyTab " + useKeyTab + " doNotPrompt " + doNotPrompt + " ticketCache is " + ticketCacheName + " KeyTab is " + keyTabName + " refreshKrb5Config is " + refreshKrb5Config + " principal is " + princName + " tryFirstPass is " + tryFirstPass + " useFirstPass is " + useFirstPass + " storePass is " + storePass + " clearPass is " + clearPass + "\n"); }
private boolean	isCurrent(sun.security.krb5.Credentials creds) Date endTime = creds.getEndTime(); if (endTime != null) { return (System.currentTimeMillis() <= endTime.getTime()); } return true;
public boolean	login() Authenticate the user return true in all cases since this LoginModule should not be ignored. exception FailedLoginException if the authentication fails. exception LoginException if this LoginModule is unable to perform the authentication. int len; validateConfiguration(); if (refreshKrb5Config) { try { if (debug) { System.out.println("Refreshing Kerberos configuration"); } sun.security.krb5.Config.refresh(); } catch (KrbException ke) { LoginException le = new LoginException(ke.getMessage()); le.initCause(ke); throw le; } } String principalProperty = System.getProperty ("sun.security.krb5.principal"); if (principalProperty != null) { krb5PrincName = new StringBuffer(principalProperty); } else { if (princName != null) { krb5PrincName = new StringBuffer(princName); } } if (tryFirstPass) { try { attemptAuthentication(true); if (debug) System.out.println("\t\t[Krb5LoginModule] " + "authentication succeeded"); succeeded = true; cleanState(); return true; } catch (LoginException le) { // authentication failed -- try again below by prompting cleanState(); if (debug) { System.out.println("\t\t[Krb5LoginModule] " + "tryFirstPass failed with:" + le.getMessage()); } } } else if (useFirstPass) { try { attemptAuthentication(true); succeeded = true; cleanState(); return true; } catch (LoginException e) { // authentication failed -- clean out state if (debug) { System.out.println("\t\t[Krb5LoginModule] " + "authentication failed \n" + e.getMessage()); } succeeded = false; cleanState(); throw e; } } // attempt the authentication by getting the username and pwd // by prompting or configuration i.e. not from shared state try { attemptAuthentication(false); succeeded = true; cleanState(); return true; } catch (LoginException e) { // authentication failed -- clean out state if (debug) { System.out.println("\t\t[Krb5LoginModule] " + "authentication failed \n" + e.getMessage()); } succeeded = false; cleanState(); throw e; }
public boolean	logout() Logout the user. This method removes the Krb5Principal that was added by the commit method. exception LoginException if the logout fails. return true in all cases since this LoginModule should not be ignored. if (debug) { System.out.println("\t\t[Krb5LoginModule]: " + "Entering logout"); } if (subject.isReadOnly()) { cleanKerberosCred(); throw new LoginException("Subject is Readonly"); } subject.getPrincipals().remove(kerbClientPrinc); // Let us remove all Kerberos credentials stored in the Subject Iterator it = subject.getPrivateCredentials().iterator(); while (it.hasNext()) { Object o = it.next(); if (o instanceof KerberosTicket || o instanceof KerberosKey) { it.remove(); } } // clean the kerberos ticket and keys cleanKerberosCred(); succeeded = false; commitSucceeded = false; if (debug) { System.out.println("\t\t[Krb5LoginModule]: " + "logged out Subject"); } return true;
private void	promptForName(boolean getPasswdFromSharedState) krb5PrincName = new StringBuffer(""); if (getPasswdFromSharedState) { // use the name saved by the first module in the stack username = (String)sharedState.get(NAME); if (debug) { System.out.println ("username from shared state is " + username + "\n"); } if (username == null) { System.out.println ("username from shared state is null\n"); throw new LoginException ("Username can not be obtained from sharedstate "); } if (debug) { System.out.println ("username from shared state is " + username + "\n"); } if (username != null && username.length() > 0) { krb5PrincName.insert(0, username); return; } } if (doNotPrompt) { throw new LoginException ("Unable to obtain Princpal Name for authentication "); } else { if (callbackHandler == null) throw new LoginException("No CallbackHandler " + "available " + "to garner authentication " + "information from the user"); try { String defUsername = System.getProperty("user.name"); Callback[] callbacks = new Callback[1]; MessageFormat form = new MessageFormat( rb.getString( "Kerberos username [[defUsername]]: ")); Object[] source = {defUsername}; callbacks[0] = new NameCallback(form.format(source)); callbackHandler.handle(callbacks); username = ((NameCallback)callbacks[0]).getName(); if (username == null || username.length() == 0) username = defUsername; krb5PrincName.insert(0, username); } catch (java.io.IOException ioe) { throw new LoginException(ioe.getMessage()); } catch (UnsupportedCallbackException uce) { throw new LoginException (uce.getMessage() +" not available to garner " +" authentication information " +" from the user"); } }
private void	promptForPass(boolean getPasswdFromSharedState) if (getPasswdFromSharedState) { // use the password saved by the first module in the stack password = (char[])sharedState.get(PWD); if (password == null) { if (debug) { System.out.println ("Password from shared state is null"); } throw new LoginException ("Password can not be obtained from sharedstate "); } if (debug) { System.out.println ("password is " + new String(password)); } return; } if (doNotPrompt) { throw new LoginException ("Unable to obtain password from user\n"); } else { if (callbackHandler == null) throw new LoginException("No CallbackHandler " + "available " + "to garner authentication " + "information from the user"); try { Callback[] callbacks = new Callback[1]; String userName = krb5PrincName.toString(); MessageFormat form = new MessageFormat( rb.getString( "Kerberos password for [username]: ")); Object[] source = {userName}; callbacks[0] = new PasswordCallback( form.format(source), false); callbackHandler.handle(callbacks); char[] tmpPassword = ((PasswordCallback) callbacks[0]).getPassword(); if (tmpPassword == null) { // treat a NULL password as an empty password tmpPassword = new char[0]; } password = new char[tmpPassword.length]; System.arraycopy(tmpPassword, 0, password, 0, tmpPassword.length); ((PasswordCallback)callbacks[0]).clearPassword(); // clear tmpPassword for (int i = 0; i < tmpPassword.length; i++) tmpPassword[i] = ' "; tmpPassword = null; if (debug) { System.out.println("\t\t[Krb5LoginModule] " + "user entered username: " + krb5PrincName); System.out.println(); } } catch (java.io.IOException ioe) { throw new LoginException(ioe.getMessage()); } catch (UnsupportedCallbackException uce) { throw new LoginException(uce.getMessage() +" not available to garner " +" authentication information " + "from the user"); } }
private sun.security.krb5.Credentials	renewCredentials(sun.security.krb5.Credentials creds) Credentials lcreds; try { if (!creds.isRenewable()) throw new RefreshFailedException("This ticket" + " is not renewable"); if (System.currentTimeMillis() > cred.getRenewTill().getTime()) throw new RefreshFailedException("This ticket is past " + "its last renewal time."); lcreds = creds.renew(); if (debug) System.out.println("Renewed Kerberos Ticket"); } catch (Exception e) { lcreds = null; if (debug) System.out.println("Ticket could not be renewed : " + e.getMessage()); } return lcreds;
private void	validateConfiguration() if (doNotPrompt && !useTicketCache && !useKeyTab) throw new LoginException ("Configuration Error" + " - either doNotPrompt should be " + " false or useTicketCache/useKeyTab " + " should be true"); if (ticketCacheName != null && !useTicketCache) throw new LoginException ("Configuration Error " + " - useTicketCache should be set " + "to true to use the ticket cache" + ticketCacheName); if (keyTabName != null & !useKeyTab) throw new LoginException ("Configuration Error - useKeyTab should be set to true " + "to use the keytab" + keyTabName); if (storeKey && doNotPrompt && !useKeyTab) throw new LoginException ("Configuration Error - either doNotPrompt " + "should be set to false or " + "useKeyTab must be set to true for storeKey option"); if (renewTGT && !useTicketCache) throw new LoginException ("Configuration Error" + " - either useTicketCache should be " + " true or renewTGT should be false");